Liquid filter arrangements and methods

ABSTRACT

A liquid filter arrangement is provided, as well as methods of assembly and use. Advantageous features, relating to a preferred filter cartridge and a preferred slide arrangement, are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. Ser. No.12/655,133, filed Dec. 22, 2009, which has now issued as U.S. Pat. No.7,955,502; which was itself a continuation of U.S. Ser. No. 11/630,705,which issued as U.S. Pat. No. 7,662,203; U.S. Ser. No. 11/630,705 havingbeen filed Dec. 20, 2006 in the U.S. as a National Stage ofPCT/US2005/021273. U.S. Ser. No. 12/655,133; U.S. Ser. No.11/630,705 andPCT/US2005/021273 each are incorporated herein by reference. A claim ofpriority to U.S. Ser. No. 12/655,133 and each of the identified familymembers is made to the extent appropriate.

This application includes, with edits, portions of: U.S. ProvisionalApplication No. 60/659,592 filed Mar. 7, 2005; U.S. ProvisionalApplication No. 60/609,602 filed Sep. 13, 2004; and, U.S. ProvisionalApplication No. 60/583,873 filed Jun. 29, 2004; a claim of priority toeach of which is made in PCT/US2005/021273. The complete disclosures ofthe three identified U.S. Provisional Applications are incorporatedherein by reference. Further a claim of priority to each of the threeprovisional applications is made, to the extent appropriate.

TECHNICAL FIELD

This disclosure relates to filtration of fluids. In particular, thisdisclosure relates to filter systems, apparatus, and methods forpurifying liquids.

BACKGROUND

Filters have been employed in a variety of applications includinghydraulic systems and engine lubrication systems. In these types ofsystems, the filter is changed periodically. One type of filtrationsystem used includes bowl-cartridge filters. Bowl-cartridge filterstypically include a reusable bowl holding a replaceable filter element(cartridge filter). Bowl-cartridge filters are typically mounted onto afilter head, wherein liquid to be cleaned passes through the filterhead, into the bowl, through the replaceable filter cartridge, outsideof the bowl, and back into the filter head. After a period of use, thebowl-cartridge filter is removed from the filter head, and thereplaceable cartridge filter is removed from the reusable bowl. The oldcartridge filter is discarded and replaced with a new cartridge filter.The new cartridge filter is operably mounted into the reusable bowl, toprovide a refurbished bowl-cartridge filter. The refurbishedbowl-cartridge filter, containing the new cartridge filter, is thenmounted onto the filter head.

SUMMARY

The present disclosure relates to liquid filter arrangements in which ananti-drain back valve assembly is provided. A variety of alternativesuseable to implement various principles in association with ananti-drain back valve assembly are described, and examples are shown.For the arrangements shown, the anti-drain back valve assembly isconstructed such that it will only allow liquid flow through the valvehead if a filter cartridge is properly positioned within a filterassembly using the filter head.

Preferred components, methods of assembly and use are also provided.

A variety of specific features that will accomplish the desirableresults, are shown. These are examples, and a variety of alternativesare possible. It is not necessary for an assembly to utilize all of theadvantageous features characterized herein, for that assembly to obtainsome advantage according to the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, cross-sectional view of a portion of a filterassembly according to the present disclosure.

FIG. 2 is a side elevational view of a filter assembly includingcomponentry according to the present disclosure.

FIG. 3 is an alternate side elevational view of the filter assembly ofFIG. 2; FIG. 3 portion being broken away to show internal detail.

FIG. 4 is a cross-sectional view of the assembly depicted in FIGS. 2 and3.

FIG. 5 is a top plan view of the assembly depicted in FIG. 4.

FIG. 6 is an enlarged fragmentary, cross-sectional view taken along line6-6, FIG. 5.

FIG. 7 is an enlarged exploded fragmentary perspective view of a portionof the assembly depicted in FIGS. 2 and 3.

FIG. 8 is an enlarged, exploded fragmentary view of the componentry ofFIG. 7, from a different perspective.

FIG. 9 is an enlarged fragmentary perspective view of the componentry ofFIGS. 7 and 8, from a different perspective.

FIG. 10 is an enlarged perspective view of a locker component used inthe componentry of the assembly of FIGS. 2-9.

FIG. 11 is a perspective view of end cap component of a filter cartridgeused in the assembly of FIGS. 2-9.

FIG. 12 is a perspective view of an alternate end cap member to the endcap member shown in FIG. 11.

FIG. 13 is an exploded view of the assembly of FIGS. 2 and 3.

FIG. 14 is an enlarged perspective view of a portion of the assembly ofFIG. 13.

FIG. 15 is an enlarged perspective view of the componentry of FIG. 14,from a different perspective.

FIG. 16 is an enlarged fragmentary view with portions broken away, ofthe assembly depicted in FIGS. 2 and 3.

FIG. 17 is an enlarged fragmentary view of a portion of the componentrydepicted in FIG. 16.

FIG. 18 is an enlarged perspective view of a portion of the componentrydepicted in FIG. 17.

FIG. 19 is a top plan view of the componentry depicted in FIG. 18.

FIG. 20 is a side elevational view of a filter cartridge useable in theassembly of FIGS. 2 and 3.

FIG. 21 is a cross-sectional view generally analogous to FIG. 4.

FIG. 22 is a top perspective view of alternate componetry useable in theassembly of FIGS. 2-19.

FIG. 23 is a top plan view of the componentry depicted in FIG. 22.

FIG. 24 is a perspective view of the componentry depicted in FIGS. 22and 23, from a different perspective.

DETAILED DESCRIPTION I. General Description of an Anti-Drain BackArrangement, FIG. 1.

FIG. 1 depicts a fragmentary, schematic, cross-sectional view of aportion of a filter assembly for purifying fluids, in particularliquids. In FIG. 1, a fragmentary view of a bowl-cartridge filterassembly is shown at 10. The assembly includes a filter head 12 and abowl-cartridge filter 14. The bowl-cartridge filter 14 includes an outerbowl, can, or housing 16, including a mounting collar 16 a, and aremovable and replaceable filter cartridge 18. The filter cartridgeincludes a cylindrical extension of filter media 20. In many typicalsystems, the filter media 20 extends between opposite end caps, one ofwhich is depicted at 22.

In FIG. 1, it can be seen that the filter housing 16 includes a regionof external threads 24. The threaded region 24 engages with threads 26on the filter head 12. Also viewable in FIG. 1 is a valve construction30. In the one depicted, the valve construction 30 operates as ananti-drain back valve 32. In typical operation, the anti-drain backvalve 32 will be open when the bowl-cartridge filter 14 is operablyassembled onto the filter head 12 and fluid is flowing therethrough. Thevalve 32 will be closed when the bowl-cartridge filter 14 is removedfrom the filter head 12. This is described further below. In addition,another feature visible in FIG. 1, and discussed further below, is asafety construction 70 that requires a filter to be installed on thefilter head 12 in order for the system to operate. In other words, if nofilter is installed on the filter head 12, there will be a highrestriction or pressure drop, which, with an appropriate sensor system,will cause an alarm, and shut down the system.

In FIG. 1, it can be seen how the filter head 12 defines an unfilteredliquid volume 34, and a filtered liquid volume 36. The unfiltered liquidvolume 34 is upstream of the filter media 20, while the filtered liquidvolume 36 is downstream of the filter media 20. In operation, liquid tobe filtered flows into the filter head 12 through an appropriate one ofopenings X and into the unfiltered liquid volume 34. From there, theliquid flows through the filter media 20 and into an open filterinterior 38. The open filter interior 38 is the volume that is inside orcircumscribed by the filter media 20. In some applications, the filtermedia 20 will have an inner liner or support 40, which is porous toallow the liquid to flow therethrough. From the open filter interior 38,the liquid flows through the valve construction 30 and into the filteredliquid volume 36. From the filtered liquid volume 36, the fluid exitsthe filter head 12 through a second one of openings X and is used by thesystem.

The valve apparatus 30 includes a cage 50, the one depicted beingcylindrical, defining open slots for example shown at 52. The slots 52allow fluid flow to pass through the cage 50. The cage 50 contains avalve seat 54. A valve head 56 is held within the cage 50 and is biasedin a position against the valve seat 54 by a spring 58. In the positiondepicted in FIG. 1, the valve head 56 is away from the valve seat 54, toput the valve 30 in an open position. When the valve 30 is in an openposition, liquid is allowed to flow from the open filter interior 38through the slots 52 and through an opening 60 defined by the valve head56. The fluid flows through the spring 58 and into the filtered liquidvolume 36 of the filter head 12.

As mentioned above, the filter assembly 10 includes safety constructionat 70. The safety construction 70 ensures that a filter 14 is properlyinstalled on the filter head 12. If a filter 14 is not properlyinstalled on the filter head 12, the valve 30 will remain in a closedposition, preventing the flow of fluid (such as oil or lubrication),causing high restriction and a signal or indicator to indicate thatthere is a problem. In the embodiment shown in FIG. 1, the safetyconstruction 70 includes a protrusion arrangement 72. The protrusionarrangement 72 actuates or engages the valve head 56 to move it awayfrom the valve seat 54, when the filter 14 is operably installed on thefilter head 12. In the embodiment shown, the protrusion arrangement 72includes a plurality of protrusions 74. In the example shown, theprotrusions 74 are integral with and preferably molded as a same part ofthe end cap 22. The protrusions 74 are depicted as hook-shaped members76 that extend into the open filter interior 38. As such, thehook-shaped members 76 are circumscribed by the filter media 20. In theone shown, the hook-shaped members 76 are adjacent and against the innerliner 40. At least two hook-shaped members 76 are typical, usually therewill be 2-4, for example 3 hook-shaped members 76.

Other features that can be seen in FIG. 1 include a seal member 80between the filter head 12 and the housing 16. There is also a sealmember 82 formed between the filter cartridge 18 and the filter head 12.In particular, the seal member 82 is between a portion of the end cap 22and a central outlet tube 84 of the filter head 12.

In operation, the arrangement of FIG. 1 works as follows: liquid to befiltered flows into the filter head 12 into the unfiltered liquid volume34. From there, it flows through the filter cartridge 18, including thefilter media 20. It then flows into the open filter interior 38 andthrough the slots 52 in the cage 50. The valve head 56 is biased awayfrom the valve seat 54 because the protrusion arrangement 70 is engagedpushing the valve head 56 away from the seal 54. This allows the liquidto flow through the opening 60, through the spring 58, and into thefiltered liquid volume 36. From there, the liquid exits the filter head12.

After a period of use, the filter media 20 becomes occluded and it istime to change the filter. To service the filter assembly 10, thebowl-cartridge filter 14 is removed from the filter head 12. Once it isremoved, the valve head 56 becomes biased against the valve seat 54because the spring 58 pushes the valve head 56 against the seat 54. Thecartridge 18 is removed from the bowl or housing 16 and replaced with anew cartridge 18. While the assembly 14 is removed from the head 12,because the valve 30 is in a closed position, liquid is not allowed todrain back and flow through the valve head 12. If someone tried tooperate the system before the filter 14 was replaced on the filter head12, because the valve 30 is in a closed position, there would be a highrestriction causing an alarm or signal to indicate that there was aproblem.

The refurbished filter 14 including the new filter cartridge 18 isplaced on the filter head 12. While the threaded engagement is madebetween the bowl 18 and the head 12, the protrusion arrangement 72engages the filter head 56. This urges the valve head 56 away from thevalve seat 54, until the filter 14 is fully, properly installed, asshown in FIG. 2.

Once the filter 14 is fully, properly installed on the filter head 12,the seals at 80 and 82 are in place, and the valve 30 is in an openposition to allow liquid to flow therethrough. The anti-drain valve 32can be constructed of stamped steel. The cartridge bowl 16 and innerliner 40 can be constructed of plastic, such as PA 6 or PA 66 or withglass reinforcement. Alternatively, metal or plastic could be chosen forthe various parts.

II. A Liquid Filter Including Locker Arrangements for Anti-Drain BackValve Arrangements

A. General Features of the Drawings.

In the figures, certain of the principles characterized above areillustrated in various embodiments, as follows.

The reference numeral 200, FIG. 2, depicts a filter assembly. The filterassembly 200 includes a filter head arrangement or filter head 202 and ahousing or bowl 203. The housing or bowl 203 can be removed from thehead, for periodic servicing. Servicing would generally involve removaland replacement of an internally received serviceable filter cartridge.

In general, the filter head 202 may have a variety of configurations.The particular filter head 202 shown in FIG. 2 would include at leastone inlet port and at least an outlet port, although variations arepossible. The particular configuration of the inlet(s) and outlet(s) onthe filter head 202 is a matter of choice for the application involved,and does not specifically concern issues described herein, except toensure proper, functional, flow into and out of the system.

In operation, the filter assembly 200 would be installed in a liquidcirculation system (hydraulic, lube or fuel for example) of equipmentsuch as a vehicle, with liquid flow (to be filtered) into the filterhead 202 through an inlet port and filtered liquid flow out of theassembly 200 through an outlet port.

In FIG. 3, an alternate side perspective view of filter assembly 200 isdepicted. In FIG. 3, an optional sensor port 211 is shown. At thislocation, a variety of sensor equipment types can be connected, forproper operation of, or monitoring of, the assembly 200.

In FIG. 5, a top plan view of assembly 200, in a particular a top viewof head 202, is depicted. An optional test port 213 is depicted.

Attention is now directed to FIG. 4 in which filter assembly 200 isdepicted in cross-section.

In FIG. 4, it can be seen that bowl 203 is removably secured to head202, by collar 203 x. In this instance a threaded connection 215 isused, with a seal provided by a seal member 216, in this example o-ring216 a. A variety of arrangements can be used for removably securing thebowl 203 to the head 202, the threaded engagement arrangement 215, withthe o-ring seal 216 a, merely being an example. A second o-ring 216 b isshown, positioned to facilitate sealing.

Still referring to FIG. 4, within interior 203 a of bowl 203, ispositioned serviceable filter cartridge 218. The filter cartridge 218 isthus a service component, and can be removed from bowl 203, and bereplaced therein, when bowl 203 is separated from head 202. In general,the filter cartridge 218 comprises a region of filter media 219 throughwhich liquid is passed, during operation, for filtering. Generallyliquid flow is outside to inside, with open central volume 220comprising a clean filtered liquid volume.

The filter cartridge 218 may include a porous inner liner 221, tosupport the filter media 219 along an inside.

Typical filter media 219 will be pleated media, for example arranged ina cylindrical configuration, although alternatives are possible for boththe media and the shape depending on the system and the needs forfiltering.

Still referring to FIG. 4 and to filter cartridge 218, the media 219 hasfirst and second opposite ends, 218 a, 218 b, and extends between firstand second end caps 222, 223. For the particular cartridge 218 shown,end cap 222 is an open end cap, with a central aperture 222 a therein.End cap 223 is closed, although alternatives are possible.

During operation, liquid to be filtered passes through head arrangement202 into liquid annulus 203 b between the bowl 203 and the filtercartridge 218. The liquid then passes through the filter cartridge 218and filter liquid exits through aperture 222 a. It then passes throughan outlet in head 202, for circulation into the machinery systeminvolved.

Attention is directed now to FIG. 6, an enlarged fragmentary view of aportion of FIG. 4. The particular assembly 200 depicted includes abypass valve arrangement 225. The bypass valve arrangement 225 isconfigured to open should the pressure in region 203 b becomesufficiently large, due, for example, to occlusion of the filtercartridge 218 (in particular media 219) from contaminant, duringextended filtering operation. This would allow a liquid bypass flowaround the filter cartridge 218, for liquid flow into region 226, andoutwardly through an outlet in the filter head 202 to avoid equipmentcavitation or other problems.

Referring to FIG. 6, it is noted that cartridge 218 (in the exampleshown end cap 222) includes an axial stem 229 thereon, with flow channelor aperture 222 a extending therethrough. The stem defines a tip 229 a,which operates as an anti-drain back valve opening (or actuating) tip,in use. The stem 229 includes an outer annular seal provided as a sealarrangement 230, in this instance an o-ring 230 a, which extends aroundstem 229. When cartridge 218 is positioned for use, stem 229 ispositioned inside of a filtered liquid flow channel 236 defined byprojection 235 in head 202, the cartridge 218 being sealed to a sealsurface defined by projection 235 by means of o-ring 230 a.

From the above, general operation of the assembly 200 will beunderstood. Many of the features detailed herein for the examplesdescribed, relate to an anti-drain back valve arrangement and preferredinteraction between the cartridge 218 and the filter head 202, in use.

Referring to FIG. 7, filter head 202 is shown in an exploded view ascomprising two general components: cover 240 and plate arrangement 241.Plate arrangement 241 includes componentry of certain valve arrangementsthereon, and is configured to be secured within cover 240. It is notedthat during normal operation and servicing, plate arrangement 241 wouldnot be removed from cover 240. The plate arrangement 241 can be securedin position within the cover 240 in a variety of manners including forexample: by adhesive or sealant; by welding; through use of a snap ringarrangement or by other mechanical connection or interlock. Theparticular method of choice would depend, in part, upon the materialsused and the type of servicing (the valve components) attended. Theparticular method is a matter of choice, for given instances ofapplication and principles according to the present descriptions. In theexample shown, bolts 241 a are used, which also ensure proper relativerotational positioning of the two components. A sealant can be used, inaddition, if desired.

Referring to FIG. 7, plate arrangement 241 defines passageway 242 which,in combination with cover 240, creates a channel or down corner forliquid to be filtered, to pass into annular region 203 b, FIG. 4. Platearrangement 241 further includes, mounted thereon, bypass valvearrangement 225.

Also, plate arrangement 241 defines central projection 245. The centralprojection 245 defines an internal filter liquid flow channel 246, FIG.8. That is, channel 246 operates as an exit channel for filtered liquid.Further, projection 245 operates to surround stem 229, when cartridge218 is in position, with seal arrangement 230 sealed thereto. That is, aportion of projection 245 defining internal channel 246 is a sealsurface for cartridge 218. (Projection 245 and channel 246, FIG. 8, areanalogous to projection 235 and channel 236, FIG. 6.)

Referring to FIG. 7, plate 241 includes anti-drain back valvearrangement 250 thereon. The anti-drain back valve arrangement 250includes a valve assembly 251 and a lock (safety) arrangement 252. Thevalve assembly 251 includes: valve piece 253 and control member 254, inthis instance comprising a biasing member 255 which is configured topress the valve piece 253 over channel 246, until a closure pressure(seal pressure corresponding to the closing force of the biasing member255) is overcome. For the example shown the biasing member 255 comprisesa coiled spring 256. (The cover 240 can include an internal center guideprojection, for the spring 256.)

In operation, valve piece 253 is biased by control member 254 to closeaperture 246 in plate arrangement 241 to liquid drain therethrough,unless the control pressure defined by biasing member 255 is overcome byfiltered liquid flow through aperture 246. Thus, valve 250 preventsdrain back of liquid from head 202 through aperture 246, when filteringfluid flow is stopped.

As indicated, the particular anti-drain back valve arrangement 250depicted, includes a lock arrangement 252, which ensures that the valvearrangement 250 is not prematurely or undesirably opened. The lockarrangement 252 comprises a moveable lock arrangement 260. The moveablelock arrangement 260 generally has a first lock orientation and a secondunlocked orientation. In general the lock arrangement 260 comprises atleast one, in this instance two diametrically (radially) opposed, lockor slide members 262 configured to have a first locked orientation,securing the valve member against movement away from the closedorientation; and a second unlocked orientation, in which the lock memberarrangement releases the valve member to allow it to move from theclosed orientation.

For the particular arrangement shown, the lock or slide members 262 areidentical to one another, and one is depicted in FIG. 10. The lockmembers 262, FIG. 10, include a slideable base 263 with a projection 264thereon. The projection 264 is positioned and sized to engage (in thisinstance to extend over a portion of) valve piece 253, FIG. 7, when thelock or slide 262 has been slid to an appropriate, locked, position.

Referring to FIG. 7, the two lock or slide members 262 are depicted inthe locked position. They are retained in the locked position by biasingmember 266, in this instance comprising a single wire spring 268.

Each one of the two lock members 262 is slidably mounted within a slidetrack 270; in this example each slide track 270 being positioned on, oras part of, plate arrangement 241. The lock members 262 can be slid inthe associated slide tracks 270 (in this instance formed integral withplate 241) between the locked position or orientation depicted in FIG. 7and an open position which will correspond to the lock members 262 eachbeing slid toward an associated end 271 of a track 270. For the lock orslide members 262 to be positioned in the open, unlocked position, i.e.,biased toward ends 271, the closing force of the biasing member 266needs to be overcome.

The biasing force of the biasing member 266 is generally overcome, i.e.,the anti-drain back valve assembly is opened (positioned to open uponliquid flow) whenever an appropriate cartridge 218 is positioned withinbowl 203 and the bowl 203 is secured to the head 202, by having axialstem 229 (in particular anti-drain back valve opening tip portion 229 a)of the cartridge 218 engage the biasing portion, edge or surface 275,FIG. 10, of each locker or lock member 262. Preferably each surface 275is configured as a cam surface. As the stem 229 is pushed into channel246, and an anti-drain back valve arrangement opening tip 229 a ispushed against biasing (cam) surfaces 275, FIG. 10, lock members 262will be actuated to unlock; i.e., forced radially outwardly in slidetracks 270, against the biasing force of the biasing member 266, FIG. 7.Thus, when a cartridge 218 (having a proper stem 229) is installed, andthe bowl 203 is secured to the head 202, the cartridge 218 will unlockthe lock arrangement 260, “opening” or allowing the anti-drain backvalve arrangement 250 to be free to operate under the biasing pressureof control member 254, in response to liquid pressures within theassembly 200.

Referring to FIGS. 7-9, it is noted that the stem 229 depicted comprisesa plurality of guide channels 280 and projections 281. In more generalterms, the particular stem 229 depicted includes a guide channelarrangement comprising at least one, typically a plurality, in thisinstance at least three (for example four) channels 280. Each preferredchannel communicates with an end of the stem 229 remote from the media219 (FIG. 7) and is positioned at a location between a location 230 x(where the seal 230 would be positioned) and the remote end of the stem229. In a typical situation in which the guide channel arrangement isused, within at least one channel, projection member 245, FIG. 8, willdefine a filter cartridge alignment or positioning projectionarrangement. The projection arrangement could include one or moreprojections, such as projection 283, FIG. 8. In operation, at least oneof the guide channels 280 would be positioned in juxtaposition (overlap)with at least one filter cartridge alignment projection. This type ofarrangement can be used to help ensure that cartridge 218 is in anappropriate position and to help prevent the cartridge 218 fromrotating, as the bowl 203 is rotated during a threading operation. Avariety of engagement arrangements between the stem 229 and theprojection 245 can be used to accommodate this. Of course, optionallythe stem 229 can be provided without such an arrangement.

In FIG. 11, a cartridge end cap 222 is shown which includes stem 229configured with guide channels 280 and projections 281. End cap 222 alsoincludes an outer periphery 285 with a plurality of radial projections286 thereon, useable as spacers to help center cartridge 218 within bowl203, during use. In the example shown, there are four projections 286.(Also, projections 286 can be used to engage the bowl 203, and help keepcartridge 218 in the bowl 203 during servicing). Stem 229 of end cap222, FIG. 11, preferably includes points or apices 281 a, on eachprojection 286 instead of blunt ends. This pointed shape can be furtherused to ensure a proper fit between the filter cartridge and filterhead. For the example shown in FIG. 11, the apices 281 a are notcentrally positioned on the projections 281, although alternatives arepossible. The apices 281 a can also be used to provide convenientactuating engagement with locks 262. An example would be with an angle(between sides 281 c, 281 d of each projection 286), around each apex281 a, of within the range of 110°-170°, for example 130°-150°, althoughalternatives are possible. Cammed (radiused or oblique) surfaces 281 balso facilitate sliding engagement with cam surfaces 275 of slides 262.

In FIG. 12, an alternate end cap 222 a is shown, having a stem 229 bwhich does not include projections, and slots or guide channels therein,but does include a mounting location 287 for an o-ring. End cap 222 afurther includes an outer periphery 285 a with spaced radial projections286 a thereon. The particular projections 286 a shown here, are shapedas fingers, to engage the bowl 203. Of course if a stem such as stem 229b is used, the plate arrangement 241 should not include projectionarrangement 283, FIG. 8.

Attention is now directed to FIG. 13, in which the assembly 200 is shownexploded. From this view, further indication of how the variouscomponents align when assembled is shown.

Attention is now directed to FIG. 14, in which a plate arrangement 241generally is shown, along with an end cap 222. In FIG. 14, withinprojection 245 is depicted v-shaped projecting member 283, althoughalternate shapes are possible. The projecting member 283 is shaped andpositioned to point toward the filter cartridge and to be engaged by oneof the guide channels 280 in stem 229 on the end cap 222. This wouldoperate, as described previously, to inhibit rotation of a filtercartridge relative to plate 241 in use. Further it can be to help ensurethat any filter cartridge installed is a proper serviceable cartridgefor the system and for proper system operation. Referring to FIG. 14, itis noted that down corner channel 242 could be formed as an aperture ora slot in a remainder of plate 241, as opposed to by an internal turn inthe outer perimeter of 241 x of the plate 241, as shown.

Referring to FIG. 15, an upper view of the components depicted in FIG.14 is shown. Viewable are: lockers or lock members 262 (in a lockedorientation); bypass valve arrangement 225; biasing member or controlmember 254; and, valve piece 253. Also, central spring 268 for sliders262 is shown.

In FIG. 16, an enlarged fragmentary view, shown with portions brokenaway, of assembly 200 is depicted. Here, the lockers (262, FIG. 15) arein an unlocked orientation, and the valve arrangement 250 is open.

In FIG. 17 an enlarged fragmentary view of a head assembly 202comprising a cover 240 and plate 241 I shown. The arrangement 202 is ina locked orientation.

In FIG. 18, a top perspective view of plate 241 is shown. In FIG. 19, atop plan view of plate 241 is shown.

B. Summary of Features and Operation Principles.

In general, according to certain aspects of the present disclosure afilter cartridge for use as a serviceable filter cartridge in a liquidfilter assembly having an anti-drain back valve arrangement is provided.The filter cartridge generally comprises a region of filter mediadefining a central open volume, the region of filter media having firstand second ends. The filter cartridge includes a first end cap securedto the first end of the region of filter media. The cartridge includesan axial stem thereon (typically on the first end cap) defining acentral liquid flow conduit therethrough, in liquid flow communicationwith a central open volume defined by the filter media. At least aportion of the axial stem projects away from the filter media. An end ofthe stem remote from the media is configured to operate as an anti-drainback valve arrangement opening (or unlocking) tip. By “opening” in thiscontext it is meant that the tip, when properly positioned, allows theanti-drain back valve to operate in an open position. The actual valveopening may be by fluid flow pressure.

The axial stem includes an outer annular seal arrangement thereon. Atypical outer annular seal arrangement would comprise an o-ring sealpositioned within a o-ring seal mounting groove on the stem.

Again, an end of the axial stem remote from the filter media wouldtypically comprise an anti-drain back valve arrangement opening tip.That is, it would be configured and positioned so that when pushed intoan appropriate receiver of a liquid filter assembly having an anti-drainback valve arrangement, it would disengage a lock arrangement to allowan anti-drain back valve arrangement to become open. Of course, again,actual opening of a preferred anti-drain back valve would be as a resultof pressure from liquid flow through the system.

The second end cap would typically be secured to the second end of thefilter media.

In a typical such filter cartridge, the anti-drain back valvearrangement opening tip would be positioned axially spaced from theannular seal arrangement.

Although alternatives are possible, for typical examples shown, theannular seal arrangement comprises an o-ring seal member, the filtermedia comprises pleated filter media, the second end cap is a closed endcap, and the filter media generally defines a cylindrical shape.Further, an inner liner would be positioned within the region surroundedby filter media, in typical applications.

An option described herein for the axial stem is a guide channelarrangement including at least one guide channel therein, positioned ata location between the o-ring seal member and the anti-drain back valvearrangement opening tip. The at least one guide channel would terminateat the anti-drain back valve arrangement opening tip, with at least oneguide channel positioned to operably engage, (juxtaposed or alignedover) a filter cartridge locating a projection arrangement within avalve assembly, during use. This can be used to help properly position afilter cartridge and retain the filter cartridge in that position,during use.

Also according to the present disclosure a filter head arrangement for afilter assembly is described. The filter head arrangement generallycomprises a cover member and a plate arrangement secured in the covermember and defining an unfiltered liquid flow channel in a centralfiltered liquid flow channel. The central filtered liquid flow channelincludes a flow exit aperture.

The filter head arrangement further includes an anti-drain back valvearrangement including a valve assembly. The valve assembly includes avalve member and a biasing member. The assembly is constructed andarranged that the valve member has a first closed orientation and asecond open orientation. When configured in the first closed orientationthe valve member is biased to close the exit aperture of the filteredliquid flow channel, by the biasing member. The biasing memberpreferably comprises a coiled spring or other valve operation memberwhich will allow opening of the exit flow aperture, under a selected ordesired liquid flow pressure through the liquid flow channel during use.

Preferred filter head arrangements according to the present disclosureare configured such that the anti-drain back valve arrangement furtherincludes a lock arrangement comprising a moveable lock (slide) memberarrangement having a first locked orientation and a second unlockedorientation. The lock member arrangement, within the first lockedorientation, is configured to secure the valve member against movementfrom the closed orientation toward the open orientation. The lock memberarrangement is moveable into the second unlocked orientation, to releasethe valve member to allow movement from the closed orientation underliquid flow pressure.

The lock arrangement preferably includes an actuator arrangement formoving the lock arrangement from the locked orientation to the unlockedorientation, upon engagement with an appropriate filter cartridge (inoperable position in association with the filter head during use). Ingeneral this is accomplished by providing a lock arrangement in the formof one or more sliders, each having an engagement portion for engagementwith a portion (including a tip) of an axial stem on a filter cartridge,when the filter cartridge is sealed in position with the axial stemprojecting to the liquid flow channel of the plate arrangement.

The lock member arrangement preferably comprises two slide membersoppositely (radially) positioned within a slide track arrangement, forradial sliding between open (unlocked) orientation and closed (locked)orientations. The movement of the lock members, and biasing toward thelocked positions, can be controlled with a single wire spring.

A particular preferred configurations for slide or lock members isdescribed and shown herein.

An arrangement in which there is positioned (within the filtered liquidflow channel of the plate arrangement) a cartridge positioning andprojection arrangement is described. This arrangement can be engaged orbe juxtaposed by a guide channel arrangement provided in the axial stemof the filter cartridge, if desired.

There is also described herein a filter assembly generally comprising afilter head assembly having selected features from those characterized;a filter bowl releasably mounted on the filter head, for example by athreaded engagement mechanism; and, a filter cartridge having featuresgenerally in accord with those described herein, operably positionedwithin the filter bowl with: an annular (for example, o-ring) sealmember on the filter cartridge axial stem sealed within the centralfiltered liquid flow channel of the plate arrangement; and, with theaxial stem of the first end cap of the filter cartridge engaging thelock member arrangement of the anti-drain back valve arrangement, tobias the lock members out of the locked orientation to the unlockedorientation.

There are also provided methods of use including a method of locking ananti-drain back valve arrangement comprising separating the filter bowlof the filter assembly from the filter head and pulling the axial stemof the filter cartridge out of the filtered liquid flow channel of theplate arrangement, to allow the lock members of the lock arrangement tobias into the locked orientation. There is further provided a method ofunlocking an anti-drain back valve arrangement comprising the opposite,i.e., pushing the axial stem of the filter cartridge into a filteredliquid flow channel of a plate arrangement as described, while sealingthe filter cartridge in place and pushing or biasing lock members orslide members of an anti-drain back valve arrangement out of a lockingorientation.

A variety of materials can be utilized for arrangements as described. Anexample would be to use cast aluminum to form the cover, the plate andthe track in the filter head, and plastic for the end cap on the filtercartridge and the lockers. Alternate materials can be used, however. Forexample, the lockers could also be aluminum.

The equipment described can be used in a variety of applications. Anexample application would be as a hydraulic filter or hydraulic fluidline of equipment such as agriculture tractors and constructionequipment.

It is noted that in typical applications, an indicator arrangement willbe utilized to show, as a result of information from a sensor equipment,the status of the system to the vehicle operator. For example, anindicator light can be used to show when pressure within the valveassembly has reached an undesirable level, for example due to the factthat the anti-drain back valve is locked close, and fluid pressurebuilds up with an annular region 203 b as a result.

III. Additional Discussion of Features and Possible Features, FIGS.20-24

Attention is first directed to FIG. 20. Reference numeral 400, FIG. 20,indicates a liquid filter cartridge. The cartridge 400 depicted can beanalogous to cartridge 218, FIG. 4.

Filter cartridge 400 generally includes media 401 extending between endcaps 402 and 403. These features can be generally as described withrespect to the arrangements discussed in connection with the assembly ofFIG. 4.

End cap 403 is a closed end cap with a projection 410 and a biasingarrangement 411, in this instance comprising spring 411 a thereon; i.e.,secured thereto. The biasing arrangement 411, in this instance spring411 a helps support the cartridge 400 within a housing, during use, toproject upwardly above a bottom of a housing in a desirable manner. Inparticular, the biasing arrangement 411 will push the cartridge, abovethe bottom of the housing, when the housing first is brought intoengagement with the filter head, to help push portions of the cartridgeup into an engagement arrangement with the filter head and to helpunlock the filter head for use in accord with the general descriptionspreviously made. On the other hand, the biasing arrangement 411, willgenerally compress or collapse as the housing is screwed onto the head,to facilitate overall assembly.

The particular spring 411 depicted, could be a coiled spring, howeveralternate arrangements can be used. Both metal and plastic arrangementscould be used. With plastic arrangements, the biasing arrangement 411could be molded as part of end cap 403.

It is also noted that end cap 403 includes spaced radially outwardlydirected projections 412 thereon, for centering within a housing, duringuse.

Attention is now directed to end cap 402. End cap 402 also includesspaced radially outwardly directed projections 413 for centering. It isnoted that a similar such projections are shown for example, on end cap222, FIGS. 1 and 4. End cap 402 is similar to the arrangement shown inFIG. 4.

In FIG. 21, assembly 420 is depicted with cartridge 400 positionedtherein. Features are generally analogous to those discussed above withrespect to other figures.

Attention is directed to FIGS. 22-24. These figures depict a plateassembly 500 analogous to assembly 241, FIG. 18. However, assembly 500utilizes a different spring arrangement 501, from the spring arrangement266, FIG. 18. In particular the spring arrangement 501 includes twospaced coiled sections 502, 503, one adjacent each of the lock members(slide members) or lockers 505, 506 respectively.

Spring arrangement 501, then, generally has a shape with three(uncoiled) segments attached to one another by coiled sections. Thisfacilitates flexibility and operation. Preferably two coils 502, 503 arespaced apart from one another a distance generally corresponding to, orslightly longer than, a distance apart of locations 502 a, 503 a,whereat spring 501 engages the opposite lock members 505, 506respectively. A general characterization of spring arrangement 501,FIGS. 22-24, then is that a long arcuate center section 501 a isprovided in extension between two coils, 502, 503. Also, springarrangement 501 includes two end sections 501 b and 501 c oppositelypositioned, in engagement with the coils 502, 503 respectively. As aresult, the coils 502, 503 are provided adjacent a point of attachmentbetween the spring arrangement 501 and the lockers 505, 506.

It is noted that in the arrangement of FIGS. 22-24, the lockers 505, 506can be either cast metal or plastic pieces.

Referring to FIG. 21, when an adhesive is also used in addition to thebolts 241 a, a trough or similar arrangement can be provided at region430 to facilitate adhesive retention where desired.

Still referring to FIG. 21, it is noted that region 432, above o-ring425, is unthreaded, and helps provide for a guiding of collar 426 andthus housing 203 in position, on filter head 202.

It is also noted that in FIG. 21 the cartridge 400 is depicted with acoiled metal inner liner 440, which would typically be made withinterlocking edges and apertures, such as louvers, therein.Alternatively in some assemblies a plastic liner could be used, and instill other assemblies a liner in the cartridge could be avoidedaltogether.

Typically when plastic materials are utilized for the opposite end caps202, 203 and the liner 440, molded nylon, for example glass reinforcednylon 66, can be used. However, alternative materials can be utilized.

By the use of such materials, a filter cartridge 400, FIG. 21, can bemade which is completely metal free for ease of disposition. With suchan arrangement, it will be preferred to utilize a plastic arrangementfor the biasing arrangement 411 a.

Referring to FIG. 21, in region 450, piston 451 extends around post 452,with motion controlled by spring 256. It is desirable to avoid trappingof liquid, such as oil, between parts 451, 452, to provide for goodmovement and control by spring 256. To facilitate this, a cut oraperture can be provided in one or both of piston 451 and post 452. Sucha cut is shown for example at 455.

In general, it is not required that all of the specific featuresdescribed herein, for example embodiments, being incorporated within anassembly, for the assembly to include advantages according to thepresent disclosure.

What is claimed:
 1. A liquid filter cartridge comprising: (a) a region of filter media defining a central, open, volume; (i) the region of filter media having first and second ends; (b) the first end cap secured to the first end of the region of filter media; (i) the first end cap including an axial stem thereon defining a central liquid flow conduit therethrough, in liquid flow communication with the central, open, volume defined by the filter media; (A) the axial stem projecting away from the media; (B) the axial stem including an outer, annular, seal arrangement thereon comprising an o-ring seal member; and, (C) the axial stem having an end remote from the o-ring seal member comprising a plurality projections spaced from one another by guide channels; each guide channel being positioned at a location between the o-ring seal member and an end of the axial stem remote from the seal; and, (D) each one of the plurality of projections having a non-blunt end defined by an apex an a pair of sides extending at an angle, around the apex, within the range of 110°-170°; and, (d) a second end cap secured to the second end of the media.
 2. A filter cartridge according to claim 1 wherein: (a) each apex is not positioned in a center of an associated end of an axial projection.
 3. A liquid filter cartridge according to claim 1 wherein: (a) the second end cap is a closed end cap having no aperture therethrough.
 4. A liquid filter cartridge according to claim 1 wherein: (a) the first end cap has an outer periphery with a plurality of spaced radially outwardly projecting projections thereon.
 5. A liquid filter cartridge according to claim 4 wherein: (a) the first end cap has an outer periphery with four radially spaced radially outwardly projecting projections thereon.
 6. A filter cartridge according to claim 5 wherein: (a) each one of the plurality of projections on the axial stem includes an end having an apex that is not positioned in a center of an end of an associated axial projection.
 7. A filter cartridge according to claim 1 wherein: (a) the axial stem includes at least 3 guide channels.
 8. A filter cartridge according to claim 1 wherein: (a) the region of filter media defines a cylindrical shape.
 9. A filter cartridge according to claim 8 wherein: (a) each apex is not positioned in a center of an associated end of an axial projection.
 10. A liquid filter assembly including: (a) an arrangement comprising: (i) a plate arrangement defining a central filtered liquid flow channel surrounding a central axis; (A) the central filtered liquid flow channel including a flow exit aperture; (ii) a side member arrangement comprising at least one moveable slide member; (b) a releasably mounted filter bowl; and, (c) a filter cartridge removably positioned within a filter bowl; the filter cartridge comprising: (i) a region of filter media defining a central, open, volume, (A) the region of filter media having first and second ends; (ii) a first end cap secured to the first end of the region of filter media; (iii) the first end cap including an axial stem thereon defining a central liquid flow conduit therethrough, in liquid flow communication with the central, open, volume defined by the filter media; (A) the axial stem including a portion projecting away from the filter media; (B) the axial stem including an outer, annular, seal arrangement thereon; and (C) an end of the axial stem remote from the filter media comprising a tip oriented to bias the at least one moveable slide member to a first orientation; and, (iv) a second, closed, end cap secured to the second end of the region of filter media; (d) the slide member arrangement comprising: (i) the at least one slide member mounted on a slide track portion of the plate arrangement and moveable toward and away from the central axis between the first orientation and a second orientation; and, (ii) a biasing member positioned to bias the at least one slide member into the first orientation; and, (iii) the at least one slide member having a filter cartridge engagement portion thereon engaged, by the filter cartridge, to bias the at least one slide member along the slide track portion, against the biasing member and in a direction away from the central axis, to maintain the slide member in the second orientation.
 11. A liquid filter cartridge comprising: (a) a region of filter media defining a central, open, volume; (i) the region of filter media having first and second ends; (b) the first end cap secured to the first end of the region of filter media; (i) the first end cap including an axial stem thereon defining a central liquid flow conduit therethrough, in liquid flow communication with the central, open, volume defined by the filter media; (A) the axial stem projecting away from the media; (B) the axial stem including a seal arrangement thereon comprising an o-ring seal member; and, (C) the axial stem having an end remote from the o-ring seal member comprising a plurality projections spaced from one another by guide channels; each guide channel being positioned at a location between the o-ring seal member and an end of the axial stem remote from the seal; (D) each one of the plurality of projections having a non-blunt end defined by an apex and a pair of sides extending at an angle, around the apex, within the range of 110°-170°; and, (d) a second end cap secured to the second end of the media.
 12. A liquid filter assembly including: (a) an arrangement comprising: (i) a plate arrangement defining a central filtered liquid flow channel; (A) the central filtered liquid flow channel including a flow exit aperture; (ii) a side member arrangement comprising at least one moveable slide member; (b) a releasably mounted filter bowl; and, (c) a filter cartridge removably positioned within a filter bowl; the filter cartridge comprising: (i) a region of filter media defining a central, open, volume; (A) the region of filter media having first and second ends; (ii) a first end cap secured to the first end of the region of filter media; (iii) the first end cap including an axial stem thereon defining a central liquid flow conduit therethrough, in liquid flow communication with the central, open, volume defined by the filter media; (A) the axial stem including a portion projecting away from the filter media; (B) the axial stem including an outer, annular, seal arrangement thereon; and (C) an end of the axial stem remote from the filter media comprising a tip oriented to bias the at least one moveable slide member to a first orientation; and, (iv) a second, closed, end cap secured to the second end of the region of filter media; (d) the slide member arrangement comprising: (i) the at least one slide member mounted on a slide track portion of the plate arrangement and moveable toward and away from the central axis between the first orientation and a second orientation; and, (ii) a biasing member positioned to bias the at least one slide member into the first orientation; and, (iii) the at least one slide member having a filter cartridge engagement portion thereon engaged, by the filter cartridge, to bias the at least one slide member along the slide track portion, against the biasing member, to maintain the slide member in the second orientation; (e) the central, filtered liquid, flow conduit of the plate arrangement including: (i) an inner, cylindrical, seal surface for the filter cartridge; and, (ii) at least one slot positioned for projection therethrough of the filter cartridge engagement portion of a slide member, when the filter cartridge axial stem is separated from the filtered liquid flow channel.
 13. A liquid filter assembly according to claim 12 wherein: (a) the axial stem includes a guide channel arrangement including at least one guide channel therein, positioned at a location between a seal member on the axial stem and the tip of the axial stem; (i) the at least one guide channel terminating at the tip.
 14. A liquid filter assembly according to claim 13 wherein: (a) the central filtered liquid flow channel includes a filter cartridge alignment projection therein; and, (b) the guide channel is positioned in overlap with the filter cartridge alignment projection. 